The Interactions API is our new interface and the most straightforward way to build with Gemini models and agents. As of June 2026, it is Generally Available and the recommended interface for all new projects.
While it is now considered legacy, the original
[ generateContent](/gemini-api/docs/generate-content/text-generation) API
remains fully supported.
Why use the Interactions API? #
New capabilities out of the box: Optional server-side conversation state usingprevious_interaction_id
, observable execution steps for debugging and UI rendering, andbackground executionfor long-running tasks usingbackground=true
.Lower cost with higher cache hit rates: Server-side state management enables more efficient context caching across turns, reducing token costs for multi-turn conversations.Built for frontier models and agents: Purpose-built for thinking models, multi-step tool use, and complex reasoning flows — simplifying the process of building, debugging, and orchestrating agentic applications.Single API for models and agents: One unified interface for calling Gemini models and agents directly such as Deep Research and custom managed agents — no separate endpoints or patterns to learn.Where new things launch: Going forward, new models and capabilities beyond the core mainline family, along with new agentic capabilities and tools, will launch on the Interactions API.
By default, the Interactions API stores requests so you can leverage
the server-side state management features by using
previous_interaction_id
. You can opt into stateless behavior by setting
store=false
. See the data retention section for details.
Get started #
Set up your coding agent: Connect to the** Gemini Docs MCP**and install thegemini-interactions-api
skill to give your assistant direct access to the latest developer docs and best practices.Set up your coding agent →Migrate from: If you have an existing integration, follow thegenerateContent
Migration Guideto transition to the Interactions API.Get started: Get started in theInteractions API Get started guide.
Feature Guides
Explore the specific capabilities of the Interactions API through these guides. You can use the toggle on these pages to switch between generateContent and Interactions API:
Text generationImage generationImage understandingAudio understandingVideo understandingDocument processingFunction callingStructured outputDeep Research AgentFlex inferencePriority inference
How the Interactions API works #
The Interactions API centers around a core resource: the . An
Interaction
Interaction
represents a complete turn in a conversation or task. It acts as a session record, containing the entire history of an interaction as a chronological sequence of execution steps. These steps include model thoughts, server-side or client-side tool calls and results (like
function_call
and function_result
), and the final model_output
. The stored resource (retrieved via interactions.get
) also includes user_input
steps for full context, though the interactions.create
response only returns model-generated steps.When you make a call to interactions.create, you are creating a new
Interaction
resource.### Server-side state management
You can use the id
of a completed interaction in a subsequent call using the
previous_interaction_id
parameter to continue the conversation. The server uses this ID to retrieve the conversation history, saving you from having to resend the entire chat history.
The previous_interaction_id
parameter preserves only the conversation history (inputs and outputs)
using previous_interaction_id
. The other parameters are interaction-scoped
and apply only to the specific interaction you are currently generating:
tools
system_instruction
generation_config
(includingthinking_level
,temperature
, etc.)
This means you must re-specify these parameters in each new interaction if you want them to apply. This server-side state management is optional; you can also operate in stateless mode by sending the full conversation history in each request.
Data storage and retention
By default, the API stores all Interaction objects (store=true
) in order to
simplify use of server-side state management features (with
previous_interaction_id
), background execution (using background=true
) and
observability purposes.
Paid Tier: The system retains interactions for** 55 days**.** Free Tier**: The system retains interactions for** 1 day**.
If you don't want this, you can
set store=false
in your request. This control is separate from state
management; you can opt out of storage for any interaction. However, note that
store=false
is incompatible with background execution and prevents using
previous_interaction_id
for subsequent turns. You can delete stored interactions at any time using the delete method found in the API Reference. You can only delete interactions if you know the interaction ID.
After the retention period expires, your data will be deleted automatically.
The system processes Interaction objects according to the terms.
Best practices #
Cache hit rate: Usingprevious_interaction_id
to continue conversations allows the system to more easily utilize implicit caching for the conversation history, which improves performance and reduces costs.Mixing interactions: You have the flexibility to mix and match Agent and Model interactions within a conversation. For example, you can use a specialized agent, like the Deep Research agent, for initial data collection, and then use a standard Gemini model for follow-up tasks such as summarizing or reformatting, linking these steps with theprevious_interaction_id
.
Supported models & agents #
| Model Name | Type | Model ID |
|---|---|---|
| Gemini 3.5 Flash | Model | gemini-3.5-flash |
| Gemini 3.1 Pro Preview | Model | gemini-3.1-pro-preview |
| Gemini 3.1 Flash-Lite | Model | gemini-3.1-flash-lite |
| Gemini 3 Flash Preview | Model | gemini-3-flash-preview |
| Gemini 2.5 Pro | Model | gemini-2.5-pro |
| Gemini 2.5 Flash | Model | gemini-2.5-flash |
| Gemini 2.5 Flash-lite | Model | `gemini-2.5-flash-lite` |
| Gemini 3 Pro Image | Model | `gemini-3-pro-image` |
| Gemini 3.1 Flash Image | Model | gemini-3.1-flash-image |
| Gemini 3.1 Flash TTS Preview | Model | `gemini-3.1-flash-tts-preview` |
| Gemma 4 31B IT | Model | `gemma-4-31b-it` |
| Gemma 4 26B MoE IT | Model | `gemma-4-26b-a4b-it` |
| Lyria 3 Clip Preview | Model | `lyria-3-clip-preview` |
| Lyria 3 Pro Preview | Model | `lyria-3-pro-preview` |
| Deep Research Preview | Agent | `deep-research-preview-04-2026` |
| Deep Research Preview | Agent | `deep-research-max-preview-04-2026` |
| Antigravity Preview | Agent | antigravity-preview-05-2026 |
SDKs #
You can use latest version of the Google GenAI SDKs in order to access Interactions API.
- On Python, this is
google-genai
package from2.3.0
version onwards. - On JavaScript, this is
@google/genai
package from2.3.0
version onwards.
You can learn more about how to install the SDKs on
Libraries page.
Limitations #
Remote MCP: Gemini 3 does not support remote MCP, this is coming soon.
The following features are supported by the
generateContent API but are not yet available in the Interactions API:
: TheVideo metadatavideo_metadata
field, used to set clipping intervals and custom frame rates for video understanding.Batch APIAutomatic function calling (Python): Note that server-side implicit caching is available in the Interactions API viaExplicit cachingprevious_interaction_id
.
Feedback #
Your feedback is critical to the development of the Interactions API. Share your thoughts, report bugs, or request features on our
Google AI Developer Community Forum.
What's next #
- Try the Interactions API quickstart notebook. - Learn more about the Gemini Deep Research Agent.